Right-click the cell that contains the field [Qty] , and click Add Total. This adds a sum of the quantity for each order to the totals row. In the empty cell to the left of Sum[Qty] , type the label  Order Total . You can add a background color to the totals row. Select the two sum cells and the label cell.
Ladder logic is the first in a series exploring different software programming methods how to choose the most appropriate model of computation based on system requirements and architecture. Future articles will cover textual, function block/data flow, state chart, and simulation and modeling methods.
ladder of inference A model that describes how individuals reach conclusions and make decisions based on facts. The model states that individuals move from observable data and experiences to selected data, added meanings, assumptions from those selected data and meanings, conclusions that are drawn, beliefs from those conclusions, and actions based on those beliefs.